Jump to content
Thunder?
Local
Radar
Pollen
IGNORED

Day 4-8 Outlook Thread


Recommended Posts

Posted
  • Location: Leigh On Sea - Essex & Tornado Alley
  • Location: Leigh On Sea - Essex & Tornado Alley

    Use this thread for Upcoming Possible Severe Model Outputs - Looks like next round of Severe Weather across the S Plains possible next weekend

    DAY 4-8 CONVECTIVE OUTLOOK

    NWS STORM PREDICTION CENTER NORMAN OK

    0340 AM CDT SUN MAR 29 2009

    VALID 011200Z - 061200Z

    ...DISCUSSION...

    SERIES OF STG SHORTWAVE TROUGHS FCST TO MOVE THROUGH LARGE SCALE

    NERN PACIFIC RIDGE AND DIG SEWD INTO CENTRAL CONUS LONGWAVE TROUGH.

    FIRST OF THESE -- NOW OVER INTERIOR PACIFIC NW -- SHOULD EJECT NEWD

    ACROSS MN ARROWHEAD/LS REGION DAY-4/1ST-2ND. ANY SVR POTENTIAL

    ALONG TRAILING FL PANHANDLE FRONTAL ZONE...CARRYING OVER FROM DAY-3

    PERIOD...APPEARS TOO MRGL/CONDITIONAL FOR CATEGORICAL OUTLOOK. NEXT

    PERTURBATION -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER PACIFIC

    DATELINE NEAR 40N -- MAY DIG SEWD ACROSS CENTRAL ROCKIES THEN PIVOT

    EWD OVER MIDDLE OR LOWER MS VALLEY DURING DAYS 4-5/1ST-3RD TIME

    FRAME. CONSIDERABLE PROG SPREAD EXISTS REGARDING AMPLITUDE AND

    LATITUDE OF THIS PERTURBATION. THAT...ALONG WITH UNCERTAIN MOISTURE

    RETURN FOLLOWING PRIOR SYSTEM...PRECLUDES CATEGORICAL SVR OUTLOOK

    ATTM.

    NEXT SIGNIFICANT WAVE -- NOW EVIDENT E OF JAPAN NEAR 40N150E --

    GENERALLY IS PROGGED TO CROSS PACIFIC AND EVOLVE INTO DEEP TROUGH

    OVER SWRN/CENTRAL CONUS DAYS 6-7/3RD-5TH TIME FRAME...THEN EWD OVER

    MS VALLEY AROUND DAY-8/5TH-6TH. THIS SYSTEM MAY YIELD CONSIDERABLE

    SVR EVENT SOMEWHERE OVER S-CENTRAL/SERN CONUS...SOMETIME DURING

    UPCOMING WEEKEND -- FRIDAY EVENING THRU SUNDAY. HOWEVER...TOO MANY

    UNCERTAINTIES REMAIN IN UPPER SYSTEM TIMING/TRACK...AND RESPONSE OF

    LOW LEVEL MASS FIELDS...TO PIN DOWN SPECIFIC OUTLOOK AREA YET.

    Link to comment
    Share on other sites

    • Replies 33
    • Created
    • Last Reply
    Posted
  • Location: Leigh On Sea - Essex & Tornado Alley
  • Location: Leigh On Sea - Essex & Tornado Alley

    Good Model Agreement now for a Severe Weather Outbreak across the Southern Plains on Saturday 4th April

    post-24-1238402582_thumb.png

    DAY 4-8 CONVECTIVE OUTLOOK

    NWS STORM PREDICTION CENTER NORMAN OK

    0328 AM CDT MON MAR 30 2009

    VALID 021200Z - 071200Z

    ...DISCUSSION...

    PROGRESSIVE SERIES OF MID-UPPER LEVEL LOWS -- EMBEDDED WITHIN

    HIGH-AMPLITUDE SHORTWAVE TROUGHS -- WILL CONTINUE TO DIP SEWD FROM

    PACIFIC INTO CENTRAL CONUS LARGE-SCALE TROUGH POSITION THEN EJECT

    EWD/ENEWD. LOW-AMPLITUDE SHORTWAVE NOW S OF AK PENINSULA SHOULD

    AMPLIFY AND DIG SEWD TO SRN HIGH PLAINS THROUGH DAY-3...PERHAPS

    DEVELOPING COMPACT 500 MB LOW AS IT MOVES FROM TX TO SRN

    APPALACHIANS DAY-4/2ND-3RD. LOW LEVEL FRONTAL ZONE IN WAKE OF DAYS

    2-3 SYSTEM SHOULD RETREAT FAR ENOUGH N TO ALLOW FAVORABLE MOISTURE

    RETURN INLAND OVER CENTRAL/ERN GULF COAST REGION...AT LEAST ACROSS

    COASTAL PLAIN...SPREADING UNDERNEATH STG MID-UPPER LEVEL HEIGHT

    GRADIENTS AND DEEP-LAYER SHEAR IMMEDIATELY PRECEDING LOW ALOFT...IN

    SUPPORT OF WELL-ORGANIZED SVR EVENT.

    NEXT SIGNIFICANT WAVE -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY

    ALONG 40N S OF WRN ALEUTIANS...SHOULD DIG SEWD ACROSS GREAT BASIN

    AND BECOME DEEP TROUGH OR CLOSED LOW OVER GREAT BASIN AND

    CENTRAL/SERN ROCKIES DAYS 5-6/3RD-5TH. TIMING STILL REMAINS

    SOMEWHAT UNCERTAIN...BUT GENERAL SCENARIO OF INTENSE SRN ROCKIES/SRN

    HIGH PLAINS TROUGH BY THEN HAS BEEN REMARKABLY CONSISTENT ACROSS

    MODELS AND FROM RUN TO RUN. PROBABILITY OF ROBUST WARM SECTOR

    RETURN FLOW AND FAVORABLE OVERLYING WINDS WITH SUCH A PATTERN BY

    DAY-6/SATURDAY/4TH-5TH...INDICATES POTENTIAL SVR OUTBREAK OVER

    PORTIONS S-CENTRAL CONUS THIS COMING WEEKEND.

    Link to comment
    Share on other sites

    Posted
  • Location: Scarborough, North Yorkshire - 80m ASL
  • Weather Preferences: Tornadoey
  • Location: Scarborough, North Yorkshire - 80m ASL

    I find it interesting that this will be happening over an area which is currently still under a bit of snow cover. I don't think this will limit potential at all. If anything, the snow melt might add to the available ground moisture and result in higher dewpoints through evaporation. I was also thinking that the depth of the recent system into the GOM might affect moisture quality, but that only seems to be a real problem for tomorrow's system, with dews rushing in behind. I'll be keeping an eye on yet another nice weekend system.

    Link to comment
    Share on other sites

    Posted
  • Location: Gosport, Hampshire.
  • Location: Gosport, Hampshire.

    I see a good virtual chase coming on for tomorrow as the outlook is continued moderate Thurs 2nd April.

    MDT RISK OF SVR TSTMS PORTIONS LOWER MS VALLEY AND

    SWRN TN TO WRN FL PANHANDLE AND SWRN GA....

    Link to comment
    Share on other sites

    Posted
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)

    Not great chase territory on the road for tomorrow's highlighted MDT risk, but nonetheless potential there for some discrete supercells with damaging tornadoes, especially near the warm front - so will be interesting to follow!

    Unfortunately no classic Plains chases look likely in the coming days, looking at at days 4-8 aswell, as the risk areas seem to be centred over SE US ... though we have a SLGT over Ern OK/NE TX today.

    Link to comment
    Share on other sites

    Posted
  • Location: Scarborough, North Yorkshire - 80m ASL
  • Weather Preferences: Tornadoey
  • Location: Scarborough, North Yorkshire - 80m ASL

    I wouldn't rule out a possible virtual chase on day 4 in nice areas just yet. Moisture is a real problem, but the LLJ is very strong. 15 degree DP's are way down in the GoM at 00z Sat morning, but they are into mid OK my mid evening. If that system was to slow down by maybe 6 hours, there'd be a decent chase up the I35 corridor. As it is progged, the moisture arrives too late and we'd be looking at an overnight squall line in eastern OK with a slight chance of some cold core action up in Northern Kansas or Southern Nebraska, before a reasonable looking event on day 5 in the same areas as tomorrow.

    Link to comment
    Share on other sites

    Posted
  • Location: Gosport, Hampshire.
  • Location: Gosport, Hampshire.

    I have never chased that far SE in the US but if it is anything like the Gulf coast of Texas it will consist of poor road networks and bad visibility due to patchy folage!...Though having said that if there was nothing else to chase in the USA whilst on vacation then I would probably still venture that way. :rolleyes:

    Today's outlook gives a different perspective from each model. Hopefully things will look clearer later on today. Storms will be ongoing throughout today along the SE Gulf Coast States along the outflow boundary ahead of the cold front. By early evening we have a significant chance for stronger storm development Central Alabama through to central west Georgia as the CAPE recedes back toward the coast. Very strong upper jet enhances storm cell development with the added risk of an isolated strong tornado! Certainly one to watch for later!

    Link to comment
    Share on other sites

    Posted
  • Location: Gosport, Hampshire.
  • Location: Gosport, Hampshire.

    An accurate severe weather forecast remains questionable within the models. Pre frontal MCS continues to saturate the atmosphere ahead of the cold font with rain cooled air. Focus for the best convection within the cold front will rely on a speedy recovery of surface temps. One tornado just reported southern MS though the cold front looks to be a very linear feature ATM. Though if we look at the combined potential instability to be released and the exceptional helicity values tornadoes remain a strong possibility over the next few hrs close to any bowing line segment. Prime positioning ATM looks to be specifically central Alabama between 21Z-00Z.

    Link to comment
    Share on other sites

    Posted
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)

    Noticed they have downgraded today's outlook to SLIGHT now, though tornado warnings abound in Nern Florida now:

    http://www.weather.gov/view/national.php?prodtype=tornado

    Seems like the ongoing convection during the day across the Gulf States has stabilised and cooled the moist returning Gulf airmass somewhat - so this seems to have lessened the chances of strong tornadoes:

    ISOLATED TORNADOES REMAIN POSSIBLE...BUT THE THREAT FOR

    MULTIPLE LONG-LIVED/DAMAGING TORNADOES HAS DECREASED JUST SLIGHTLY

    ACROSS THIS REGION.

    Maybe we should start dedicated virtual threads in the new 2009 storm chase area?

    Link to comment
    Share on other sites

    Posted
  • Location: Leigh On Sea - Essex & Tornado Alley
  • Location: Leigh On Sea - Essex & Tornado Alley

    Going to leave the Virtual Threads in here if thats okay Nick, leave the Storm Chase 2009 Thread for Day to Day Reporting when we are out there, there will also be a Thread dedicated to our Live Streaming.

    Tony SPC Sometimes come up with funny Charts, Remember the Storm Report that said Elephants were Running Loose in Wakeeney (Ks) :)

    Paul S

    Link to comment
    Share on other sites

    Posted
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)

    Right you are Paul ... :good:

    Link to comment
    Share on other sites

    Posted
  • Location: South Shields Tyne & Wear half mile from the coast.
  • Location: South Shields Tyne & Wear half mile from the coast.
    LOL

    How rude is that :good:

    post-24-1238704033_thumb.png

    I think the best place to be would be here.

    Link to comment
    Share on other sites

    Posted
  • Location: Leigh On Sea - Essex & Tornado Alley
  • Location: Leigh On Sea - Essex & Tornado Alley

    DAY 4-8 CONVECTIVE OUTLOOK

    NWS STORM PREDICTION CENTER NORMAN OK

    0348 AM CDT FRI APR 03 2009

    Wow

    Moisture really is a problem this year it seems, another Cold Front clearing the Gulf Of Mexico of Moisture and end of next weeks System coming across from the Desert SW Looks to be starved as well, so right up to the 11th looks likely to be a "No Go" for Severe, April looking benign until Mid Month at least it seems!

    VALID 061200Z - 111200Z

    ...DISCUSSION...

    A SEASONABLY COLD UPR TROUGH WILL SLOWLY BEGIN TO TRANSLATE OUT OF

    THE ERN CONUS DURING MID-LATE NEXT WEEK. CDFNT ASSOCD WITH THIS

    TROUGH WILL CLEAR THE ENTIRE GULF OF MEXICO...ENDING CONCERNS FOR

    WIDESPREAD SVR WEATHER THROUGH AT LEAST WEDNESDAY.

    THE NEXT UPR LOW IS PROGGED TO QUICKLY MOVE ACROSS THE DESERT SW ON

    TUESDAY AND ARRIVE IN THE SRN PLNS LATE WEDNESDAY AND THURSDAY.

    SYSTEM WILL THEN MOVE INTO THE OH VLY/DEEP SOUTH DURING THE END OF

    NEXT WEEK. SPEED AND ORIENTATION OF THE TROUGH SUGGESTS THAT

    DESPITE ANY STRONG RETURN FLOW DEVELOPMENT...ONLY MODIFIED NW

    CARIBBEAN/GULF MOISTURE WILL ARRIVE AHEAD OF THE SYSTEM. THIS WILL

    TEMPER THE SVR RISKS ASSOCD WITH THE LATE WEEK SYSTEM AND WILL

    PRECLUDE A HIGHER-END MEDIUM RANGE SVR OTLK.

    Link to comment
    Share on other sites

    Posted
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)

    Although its a long way off, GFS and SPC hinting at a severe outbreak next weekend - atm for Texas and parts of Sern/High Plains through the Gulf States area ... as a much more amplified upper trough moves in from the west coast and amplifies as it crosses SW USA. sfc lee low sits on the eastern edge of the Rockies getting some much needed moisture return hopefully:

    00z Sunday 12th April (18z Sat US time):

    post-1052-1238941238_thumb.pngpost-1052-1238941252_thumb.png

    post-1052-1238941353_thumb.png

    Chance of some slights this week, though mositure return looks limited.

    SPC hints at this in the 4-8 day outlook:

    DAY 4-8 CONVECTIVE OUTLOOK

    NWS STORM PREDICTION CENTER NORMAN OK

    0345 AM CDT SUN APR 05 2009

    VALID 081200Z - 131200Z

    ...DISCUSSION...

    AN AMPLIFIED PROGRESSIVE FLOW REGIME WILL EXIST FROM WED INTO NEXT

    WEEKEND. A PARADE OF UPR LOWS WILL AFFECT THE SRN TIER OF THE

    COUNTRY...BUT CONFIDENCE ON THE TIMING OF EACH ENTITY IS BELOW

    AVERAGE. LEAD SYSTEM...PART OF WHICH WILL ARRIVE IN CA ON

    TUE/WED...WILL EVENTUALLY TRANSLATE ACROSS THE CNTRL/SRN PLNS AND

    THE SRN STATES IN THE THU-SAT TIME FRAME. RETURN FLOW WILL ADVECT A

    MODIFIED GLFMEX AIR MASS NWD AND OFFER SOME SVR THREAT ACROSS THESE

    AREAS...BUT IT DOES NOT APPEAR TO BE A WIDESPREAD EVENT. MORE

    IMPORTANT EVENT MAY ARRIVE NEXT WEEKEND...THOUGH TIMING AGAIN IS

    UNCLEAR. THIS SYSTEM COULD HAVE BETTER MOISTURE AVAILABILITY AND

    OFFER A HIGHER SVR RISK THAN ITS PREDECESSOR. UNTIL MEDIUM RANGE

    MODELS COME IN BETTER AGREEMENT...A SVR RISK WILL NOT BE INTRODUCED.

    ..RACY.. 04/05/2009

    Chance of some slights this week, though mositure return looks limited. Next weekend's potential still uncertain, but 00z ECM looks fairly good also:

    post-1052-1238941816_thumb.pngpost-1052-1238941843_thumb.png

    Fingers crossed ...

    Link to comment
    Share on other sites

    Posted
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)

    Following on from the earlier hints above, Models begining to fall into place for a possible severe few days on Saturday for TX, then further east for Sunday:

    post-1052-1239103992_thumb.png

    DAY 4-8 CONVECTIVE OUTLOOK

    NWS STORM PREDICTION CENTER NORMAN OK

    0350 AM CDT TUE APR 07 2009

    VALID 101200Z - 151200Z

    ...DISCUSSION...

    THE MEDIUM RANGE WILL CONTINUE TO SEE THE PATTERN OF ERN PAC

    SHORTWAVE TROUGHS AMPLIFYING INTO CLOSED LOWS ALONG THE CA

    CST...THEN EJECTING EWD INTO THE SRN PLNS. THE LEAD UPR SYSTEM THAT

    IS LIKELY TO PRODUCE A ROUND OF SEVERE WEATHER ON THU-THU NIGHT

    ACROSS THE SRN PLNS...OZARKS AND MID-SOUTH WILL EJECT NEWD THROUGH

    THE TN/OH VLYS AND WEAKEN ON FRIDAY. MODIFIED GULF MOISTURE

    ENTRAINMENT IS LIKELY AS FAR N AS THE TN VLY AND SOME SVR MAY OCCUR

    IN THAT AREA ON FRIDAY...THOUGH NOT WIDESPREAD ENOUGH FOR A MEDIUM

    RANGE SVR OUTLOOK.

    00Z ECMWF/GFS ARE WITHIN REASONABLE AGREEMENT REGARDING THE SECOND

    UPR LOW PROGGED TO MOVE INTO THE SRN HIGH PLAINS SATURDAY NIGHT.

    LLVL MOISTURE WILL NOT BE SHOVED TOO FAR S BY THE LEAD SYSTEM AND

    SHOULD RAPIDLY RETURN NWD INTO TX. AVAILABILITY OF RICHER THETA-E

    AND DEVELOPMENT OF THE LEE-LOW/DRYLINE ACROSS WCNTRL TX WILL BE FOCI

    FOR SATURDAY EVENING TSTM DEVELOPMENT. SSWLY LLJ SHOULD INTENSIFY

    SATURDAY NIGHT WITH A POSSIBLE ORGANIZED SVR EVENT EVOLVING

    OVERNIGHT SATURDAY NIGHT/EARLY SUNDAY ACROSS CNTRL/ERN TX.

    AS THE UPR SYSTEM CONTINUES TO INTENSIFY...LARGER SCALE HEIGHT FALLS

    WILL SPREAD TOWARD THE LWR MS/TN VLYS SUNDAY. ATTENDANT SFC LOW

    SHOULD MIGRATE NEWD ALONG THE INTENSIFYING WRMFNT TOWARD TN SUNDAY

    NIGHT WITH A STOUT SWLY LLJ TRANSLATING EWD THROUGH LA...MS AND AL.

    ORGANIZED SVR WEATHER WILL PROBABLY DEVELOP UPSCALE FROM THE MORNING

    ACTIVITY ACROSS ERN TX AND REACH THE TN VLY-DIXIE SUNDAY NIGHT.

    ..RACY.. 04/07/2009

    There is a SLIGHT before then out for Thursday east of the I-35 and west of the Mississippi:

    http://www.spc.noaa.gov/products/outlook/day3otlk.html

    Link to comment
    Share on other sites

    Posted
  • Location: Leigh On Sea - Essex & Tornado Alley
  • Location: Leigh On Sea - Essex & Tornado Alley

    Looking like the active Period to continue with Severe Storms expected Thur and Fri this week.

    post-24-1239614647_thumb.png

    DAY 4-8 CONVECTIVE OUTLOOK

    NWS STORM PREDICTION CENTER NORMAN OK

    0328 AM CDT MON APR 13 2009

    VALID 161200Z - 211200Z

    ...DISCUSSION...

    LATEST MODEL GUIDANCE CONTINUES TO SUGGEST HEIGHTS WILL FALL OVER

    THE SRN ROCKIES/HIGH PLAINS AS UPPER LOW SETTLES INTO THE 4-CORNERS

    REGION THURSDAY. THIS FEATURE SHOULD THEN SLOW ITS EWD PROGRESSION

    INTO THE HIGH PLAINS DUE TO DOWNSTREAM RIDGE THAT IS ANCHORED NEAR

    THE MS VALLEY. STRONGER FLOW WILL EVENTUALLY OVERSPREAD A GRADUALLY

    MOISTENING BOUNDARY LAYER ACROSS THE SRN HIGH PLAINS AND THIS SHOULD

    RESULT IN A MULTI-DAY CONVECTIVE EVENT ACROSS MUCH OF TX/OK/KS/NEB.

    WITH DEEP CONVECTION EXPECTED TO INTERCEPT THE GREATEST INSTABILITY

    ACROSS TX/OK SEVERE THUNDERSTORM THREAT MAY BE LIMITED FARTHER

    NORTH...DESPITE CONVECTIVE POTENTIAL WITHIN OTHERWISE FAVORABLE

    ENVIRONMENT FOR ORGANIZED SEVERE STORMS. GIVEN THE EXPECTED SLOW

    MOVEMENT OF UPPER SYSTEM NUMEROUS THUNDERSTORM CLUSTERS AND MCS/S

    SHOULD EVOLVE DURING THE DAY4-5 TIME FRAME.

    Link to comment
    Share on other sites

    Posted
  • Location: Leigh On Sea - Essex & Tornado Alley
  • Location: Leigh On Sea - Essex & Tornado Alley

    DAY 4-8 CONVECTIVE OUTLOOK

    NWS STORM PREDICTION CENTER NORMAN OK

    0346 AM CDT SAT APR 18 2009

    VALID 211200Z - 261200Z

    ...PREDICTABILITY TOO LOW TO DELINEATE A SEVERE THREAT AREA...

    MEDIUM RANGE FORECAST GUIDANCE INDICATES THAT THE AMPLIFIED UPPER

    TROUGH WILL LIFT OUT OF THE EASTERN STATES DURING THE MIDDLE TO

    LATTER PART OF THE COMING WORK WEEK...WITH A TENDENCY FOR INCREASED

    TROUGHINESS IN THE WEST. THIS WILL UNDOUBTABLY CONTRIBUTE TO

    INCREASING CONVECTIVE POTENTIAL ACROSS PARTS OF THE INTERMOUNTAIN

    WEST INTO THE PLAINS...WHERE LAPSE RATES WILL STEEPEN.

    HOWEVER...MODELS GENERALLY SUGGEST THAT A STRONG MOISTURE RETURN

    INTO AND THROUGH THE PLAINS IS UNLIKELY UNTIL AT LEAST NEXT WEEKEND. WHILE POCKETS OF STRONGER DESTABILIZATION ASSOCIATED WITH SHORT

    WAVELENGTH PERTURBATIONS EMBEDDED WITHIN THE LARGE-SCALE FLOW MAY

    YIELD NON-NEGLIGIBLE SEVERE POTENTIAL THROUGH THE PERIOD...THE

    SPREAD AMONG NCEP MREF MEMBERS CONCERNING THESE FEATURES IS QUITE

    LARGE. THIS LIMITS THE ABILITY TO CONFIDENTLY ASSESS AND DELINEATE

    THE RISK FOR A REGIONAL SEVERE WEATHER THREAT.

    Well that is a pretty good 4-8 Day in my Book and lets just hope the Systems dont rip up the Plains on Saturday and Sunday and gets pushed back a few days.

    Regarding the Outlook for the 1st Chase Day proper and the rest of that week, Models are STILL Showing Troughs ploughing through from the West Coast!

    Paul S

    Link to comment
    Share on other sites

    Posted
  • Location: south London
  • Location: south London

    So it might be a chase around Texas,Okl or Kans.. Paul for this day :)

    Havent seen CAPE this high here before :mellow:

    and a good Jet Stream on this date..

    Link to comment
    Share on other sites

    Posted
  • Location: Leigh On Sea - Essex & Tornado Alley
  • Location: Leigh On Sea - Essex & Tornado Alley

    Latest From the SPC - Which now covers our arrival - Things to Note from this is the Amplified Pattern Setting up which is what we wanted to See, Problems at the moment seem to be the Members differing on the Evolution of the 1st Big Trough, GFS Has slowed this down, ECMWF Is looking favourable as the Low gets stuck in the Plains for around 3-4 Days, so as soon as these differences get Sorted in the next few days would expect to see a Day 5,6,7 or 8 Risk on the 4-8 Day Page!

    DAY 4-8 CONVECTIVE OUTLOOK

    NWS STORM PREDICTION CENTER NORMAN OK

    0345 AM CDT SUN APR 19 2009

    VALID 221200Z - 271200Z

    ...PREDICTABILITY TOO LOW TO DELINEATE A SEVERE THREAT AREA...

    MEDIUM RANGE FORECAST GUIDANCE CONTINUES TO SUGGEST THAT A

    TRANSITION FROM A WESTERN RIDGE/AMPLIFIED EASTERN TROUGH TO

    AMPLIFIED WESTERN TROUGH/EASTERN RIDGE WILL TAKE PLACE DURING THIS

    FORECAST PERIOD. THIS PROBABLY WILL BE ACCOMPANIED BY A SUBSTANTIVE

    RETURN FLOW OF MOISTURE OFF THE GULF OF MEXICO... THROUGH THE

    CENTRAL/SOUTHERN PLAINS INTO THE UPPER MISSISSIPPI VALLEY...LATE

    THIS COMING WORK WEEK INTO NEXT WEEKEND. AT THE SAME TIME WARM

    ELEVATED MIXED LAYER AIR SHOULD ALSO ADVECT EAST OF THE

    ROCKIES/PLATEAU REGION...CONTRIBUTING TO INCREASING INSTABILITY AND

    CONVECTIVE POTENTIAL AS IT OVERSPREADS THE LOW-LEVEL MOISTURE.

    HOWEVER...THE SPREAD AMONG THE MODELS... INCLUDING THE MREF

    MEMBERS...CONCERNING THE SHORT WAVE DEVELOPMENTS WITHIN THE

    LARGER-SCALE PATTERN IS VERY LARGE AS EARLY AS DAY 4...AND REMAINS

    SO THROUGH THE BALANCE OF THE FORECAST PERIOD. THIS CONTINUES TO

    LIMIT THE ABILITY TO CONFIDENTLY ASSESS AND DELINEATE THE RISK FOR A

    SEVERE THREAT AREA.

    Link to comment
    Share on other sites

    Posted
  • Location: Scarborough, North Yorkshire - 80m ASL
  • Weather Preferences: Tornadoey
  • Location: Scarborough, North Yorkshire - 80m ASL

    Currently sat in a hotel in Basingstoke where I am on a course all week, but I'm trying to keep an eye on how things are looking. the ECMWF is showing a nice trough over the western US moving into a nice position for Monday, but then retrogrades this back west a little which may temper the following days somewhat. I'd imagine that may then eject east later in the week giving more severe chances although this may be a bit further north than the current gfs indicates. Monday looks really good with a 850mb wind peak around the panhandles and into W Kansas. Could be steak for dinner in the Big texan at the end of the day? :lol:

    The Last time I looked at the GFS, it wasn't quite as bullish and I think was a bit quicker which wouldn't be as good for you guys, but the new run is coming through at the moment and I can't check it out. I'm a big follower of the ECMWF models anyway so hopefully you should set off with a bang.

    Link to comment
    Share on other sites

    Posted
  • Location: Leigh On Sea - Essex & Tornado Alley
  • Location: Leigh On Sea - Essex & Tornado Alley

    I have a Feeling that when the 4-8 day Updates in the next few hours there will be quite a good Risk day and Hatched area for Day 5!! :)

    Saturday looking a very good Chase Day in Oklahoma from current Models.

    Paul S

    Link to comment
    Share on other sites

    Archived

    This topic is now archived and is closed to further replies.

    ×
    ×
    • Create New...